a = [1, 2, -1, 4, 5, -5, 7, -3, -9, 10, 11]
b = [i for i in a if i > 0]
# 使用format或f-string来格式化字符串
print(b)
print(f"大于0的个数是: {len(b)}")   # 或者使用老版本的format方法: print("大于0的个数是: {}".format(len(b)))
c = [i for i in a if i < 0]
print(c)
print(f"小于0的个数是: {len(c)}")


a = "axbyczdj"
print(a[1:7:2])# 每隔两个取一个



a = "hello_world_yoyo"
b = a.split("_")
print(b)


a=input("请输入：")
print(a)

name=input("请输入你的名字：")
print(f'I am{name}and I am studying Python in Nowcoder!')